An implantable ocular device designed to permanently fill the orbital cavity following enucleation, evisceration, or after the removal of another ocular implant (used as a secondary implant), to replace the volume and possibly, given the surgical method, to impart motion to the eventual ocular prosthesis (the artificial eyeball). It is typically aspherical and may have porous surfaces to facilitate colonization by fibrovascular tissue to offer the advantages of reduced risk of infection or implant extrusion. It is available in various sizes and is typically made of polymethylmethacrylate (PMMA), poly 2-hydroxyethylmethacrylate (PHEMA), or silicone.